Existing Boiler piping critique

Clance

Hi Everyone. Been trolling the wall for a couple weeks trying to learn about single pipe steam. Been reading Lost Art too. I'm impressed with you all and your knowledge and helpfulness! I'm lucky to have a contributor to this forum coming out soon to replace both boilers for my 2 family house just north of Boston. I am confident that he will do a great job - I'm super excited! Replacing both PV84s with MegaSteam 288s. I want to be a smart as I can in maintaining the new and figured understanding the piping and it's purpose/job is a good place to start.
So, I went down cellar and looked at one of my boilers (the only one that still works!) to test what I have learned. Just for fun I drew up exactly what my near boiler piping looks like and then I picked apart the current installation to test my knowledge of what I've learned here. If anyone has extra time on their hands - take a look at the attached photo and "grade me" Would love to hear what I have I gotten wrong or right or missed in my attempt to spot any "Issues" of my exiting boiler. Pic attached. Cheers! Rick
PS - I hope this post isn't in appropriate:)

ethicalpaul

Looks pretty good! My amateur opinion is that you are too critical of your hartford loop piping. 1-1/4 is probably fine.

I don't think there can be too much A height within reason.

You will make things easier on yourself and probably others to forget BTU for radiator and boiler sizing and just compare the EDR of the radiators in sq feet directly against the "net sq feet of steam" value of whatever boiler you are looking at. If you talk in BTU there are always followup questions like "is that input or output?" and "is that before or after pickup factor?"

Congratulations, you know more than 99.9% of the world's population about steam heat!

PS: do you have a main vent?

EBEBRATT-Ed

@Clance

Good job Rick.

A few comments

The header must be at least 24" above the boilers normal water line...not the top of the boiler. More is better.

# of risers must be in accordance with the boiler MFG recommended piping. Some small boilers are ok with 1 riser

Bull head tee is a no no. Two supplies should be fed with two risers from the top of the header

The Hartford loop should be connected to the equalizer 2-4" below the normal water line (but follow what the boiler mfg recommends).

Basically you just follow what the boiler MFG want's in the piping diagram that comes with the boiler and skimming the boiler after it is installed

Also make sure the main venting and radiator vents are up to snuff

Good luck with your new install. Post a few pictures when complete.

Clance

@ethicalpaul
@EBEBRATT-Ed

Thanks for your insights, pretty soon I'll start learning more about Venting, especially the radiators. So will start to think in terms of Sq Ft EDR. Leaving the main vents (and everything else about the installs) up to the knowledgeable steam installer. He's planning a 2" dropped header.

Neither of my steam systems piping have any main vents anywhere, but one does have an 8" capped riser about 1' in form the end of a run...which probably was one- There really is no sign of vents anywhere else.
It's all very fascinating and the fact that steam can be so picky makes it a lot of fun to learn about... the challenge of trying to bring back to life what was once probably a well planned system when installed.

Is it possible that the system is so small that the one main vent at the end of on one branch when combined the rad venting could have been considered sufficient? Here's a pic of an aerial drawing of the system.. should there be big vents at the end of each branch?

ethicalpaul

Youngplumber said:

@ethicalpaul I think the Hartford loop pipe size will come with the boiler instructions. 

Absolutely. But he was critiquing his existing system and I was critiquing his critique as he requested. In those terms, a 1-1/4" hartford loop would not be worthy of concern to me.

ethicalpaul

Is it possible that the system is so small that the one main vent at the end of on one branch when combined the rad venting could have been considered sufficient? Here's a pic of an aerial drawing of the system.. should there be big vents at the end of each branch?

If it were me, I'd want to have at least a small main vent at probably 3 places but it's hard for me to say without understanding more of what's going on. It is likely that when they made it, there was far less concern about main venting because they were running a coal fire 24/7. But like you said your installer if they are adherents to TLAOST will know what to do.

For your question on the drawing about the return that doesn't get hot, it's because there is air trapped in there keeping the steam out. This isn't bad...it would happen even if that suspected main vent port were populated with a vent instead of capped.

Clance

@ethicalpaul
About the return staying cold - if that length of return isn't getting hot doesn't that imply the there is no condensation flowing back through it... and that it's not doing it's job? Wouldn't that mean that that the condensation it would normally carry back is now backing up into the steam pipe instead of flowing back through the return? All the other returns are very warm to the touch.

ethicalpaul

I can't see the pitch of course, maybe it's counterflowing there back down the main. but keep in mind it looks like only a single radiator on that leg, and condensation doesn't have much heat content compared to steam.

Clance

@ethicalpaul
Thanks! I know its cold because there is 0 insulation on anything
Got a bunch delivered yesterday in prep for the new MegaSteams, ordered 1.5" for the steam pipes and 1" on the returns. Sure gonna miss my nice warm basement.

ethicalpaul

Yeah sometimes the manufacturer specifies some weird things. They definitely don’t want to specify an over-engineered solution because their installers’ estimates will tend to come in high and they’ll sell fewer boilers.

JUGHNE

Youngplumber, I believe they don't WANT the 2nd opening not to be used....rather they just say if not used then be sure to plug that opening. Seems like an obvious doesn't it? But for liabilty reasons they cover that base.

As Paul said the manufactor wants to publish the easiest way for piping. Possibly making the piping borderline operational.
I have noticed some newer side outlet boilers now have only 2" hubs rather than the almost always 2 1/2" not to be reduced outlets.
It is a big jump from 2 to 2 1/2", fittings and threading cost a lot more.
2" is often the largest threading equipment for many people.....me included.

kenlmad

How is it possible that the pitch of the pipes exiting the bullnose tee are opposite? In other words, each branch leaves the tee going downhill? One has to be going up hill and one downhill.

Unless it is dead flat pitch, one branch is counterflow and the other branch is parallel flow. Counterflow is returning condensate against the steam supply until it reaches the tee and then is part of the parallel flow branch. Thus, the counterflow branch return is cold.

Clance

@kenlmad
HI. I confirmed that the pitch on the pipes coming out of the bull T goes in opposite directions. The pipe to the right is about 2' long then a 90 degree turns it toward the front where it continues to pitch in the same direction. It ends at a drop into the return line. I not a pipe fitter or plumber but that seems to make sense as the condensate flows with the steam the entire way then drops into the return at the end which is pitched back to the boiler. See the 1st Picture.

The second picture of of the end of the pipe that comes out of the Bull T to the left. It also pitches away and drops into the return at the end and the return is pitched back to the boiler. So it seems like the condensate would travel with the steam in both pipes, then the condensate drops into the the ... No?

This was my grand partent's house and I remember the of coal/oil conversion boilers... they were beautiful- looked like a lady when I was little (as I rode my Big-Wheel around them) - up on decorative curved legs with a belly and a top and a hat with egg-n-dart decorations all around the skirt on the midsection,
The 3rd photo is of the current boiler, the original was replaced in the early 1980s and this on was put in by me (or rather paid for by me back in 2001. All the silver painted pipes are pretty much original parts of the system. Look at the Hartford Loop, In my critique I said the tie in to the equalizer was too high and @EBEBRATT-Ed confirmed that the loop usually ties in below the water line. (I also said the equalizer was tied in at the wrong spot).

But, as I read more of Dan's book he mentions that often that original water level gets lost when replacements are installed... so I have new observation... knowing that the hartford loop is original to the system... perhaps its not the tie in of the Hartford loop that's too high but rather the boiler is too low relative to the original water line as defined by the original hartford loop! ?? Any thoughts on that?
Cheers, Rick

Clance

@kenlmad 1st image didn't load om my last post so here's the pipe out to the right from Bull T (Bull T is right above the sheetrock/fire barrier.) if you look close you can even see that the pipe pitches right. The perspective of the pic is from the end where it drops into the lower condensate return. And see the capped riser... bet it's supposed to have a vent

EBEBRATT-Ed

@kenlmad
is correct about not being able to pitch down on both sides of a bullhead tee, I think I mentioned that in a previous post as well. The only reason it works is the pipe on one side is very short and that small amount of counterflow doesn't matter

Clance

@EBEBRATT-Ed
Thanks for the follow up explanation. About my Hartford loop question, assuming my loop height is original to my system (which I think it is)... have they always traditionally been installed a bit below the water line? So would the height of my loop indicate that the original planned system water line was closer to where the loop top is -and thus about 10" higher than water line on my current boiler. And if that's the case, would it have been a good idea for installer to have raised the boiler higher to try to get closer to the original water line? Just curious.

clammy

I think I would just re do all of the near boiler piping and split that bull head and do a drop header w 3 tee s 2 for the 2 inch supply and a smaller for the 1 1/2 supply . If any of the mains are counter flow then pipe a drip into the wet return and feed into the counter flow from the top that way there’s never a issue and is the best way to pipe a counter flow with out issue from my experiences . As for the equilizer it may be over kill but all the streams I do have a 2 inch equilizer and it the return tapping is 2 1/2 we use a 2 1/2 nipple and a 21/2 by 2 tee to pick up the equilizer . The tee facing so the bottom may be flushed and wanded as needed for cleaning this is usually over looked ll add flush valve to the unused return it s good practice for further flushing if required . With out really looking into the size of the boiler a minimum of a 3 inch header is what I usually do no sense in going smaller you really need that larger pipe size to lower velocity and help produce more useful dry steam . Best of luck on your project peace and good luck clammy

Clance

@clammy
Thanks for the info! The plan on Thursday is to have installed a MegaSteam MST288 (Net 69K BTU) with two 2" risers into a dropped 2" header. I have confidence in the pipefitter doing the job as he often posts photos of his work on this site and get lots of accolades and contact recommendations. I did ask him about installing a 3" header few weeks ago and he said that 2" will do just fine as it is such a small boiler. But it sounds like you would go with 3" on the header, even though its on the smallest MegaSteam made...

I have a 2 family and am replacing both boilers... 1st one is schedule for Thursday - originally just doing one for my apartment but when I was cleaning up the cellar to make room I noticed the other was short cycling and auto filling with water (20-30 seconds of water) every cycle - all day long. So I looked up at the chimney and the pic attached is what I saw... looks like steam. So my tenant is now getting my boiler and my unit got reschedule until mid Feb. My pipe fitter was very good about the sudden change in the plan, which I appreciated. Nothing against my oil guy that did the existing boilers - But I'm excited to see and have one installed Thursday by a guy that really knows the nuances of stem systems. In fact, my oil guy seems pretty excited too - he actually asked if he could come over and watch the install -he's 70 years old and still wants to learn, god bless him!

clammy

Sounds like you have the right guy and it is a smaller boiler ,2 1/2 would be my min.for using 2 taps and and w counter flows slows always the way to go . Peace and good luck clammy

Clance

I appreciate the time and input and advise form everyone. Yeh- This is a learning exercise for me, 24 years I lived with steam heat and never learned about it. It's fascinating. I would not be so bold as to 2nd guess the installer putting in my boiler - he's a steam guy and seemingly successful at it. I feel kind of lucky he's willing to make the trek to north of Boston.

I believe that a professional who has excelled in their chosen career certainly knows more than me in their realm. And so I like to ask them why and why not.

If any one cares I just posted a new discussion - asking about installing vents my risers instead of valves.
Heres this link
https://forum.heatinghelp.com/discussion/182879/install-vents-on-risers-single-pipe-system#latest